Evaluation of some biological properties and grain yield of five chickpea cultivars in weed appearance

In agriculture, weeds are one of the main limiting factors. In fact, the problem of weeds is a basic problem in farms, which can lead to major economical yield losses in agriculture. Weeds can decrease soil nutrients and can threaten crops by competition for water, nutritions and light. Chickpea (Cicer arietinum L.) is one of the earliest cultivated legumes and 7500-years old remains have been found in the Middle East. It plays an important role in human nutrition as a source of protein, energy, fiber, vitamins, and minerals for large population sectors in the developing world. The weeds in chickpea fields in some cases has caused a 90% decrease in yield. This research was conducted to evaluation of some biological properties and grain yield of five chickpea cultivars in weed appearance in natural conditions.

The experiment was conducted at the Research Farm Bu-Ali Sina University (latitude 35◦1' N, longitude 48◦31' E and 1690 m altitude) during 2013 and 2014 growing seasons. Experiment was conducted as factorial based on randomized complete block design (RCBD) with three replications. Experimental treatments included weed control (weeding and non-weeding) and chickpea cultivars (Tork, Hashem, Arman, Azad and Mahali). The total amount of rainfall during the experiment in the first and second years was about 76 and 80 mm, respectively. The evaluated chickpea traits were plant height, leaf area, branches number per plant, biological and grain yield, chlorophyll index and nodule number and weight. Analysis of variance was used for statistical analyses (Version 9.2, SAS). Differences between treatments were compared by least significant difference (LSD) test at 5% probability.

Analysis of variance showed that the effect of weed control on all traits. Also, the effect of cultivar was significant for all traits except chlorophyll index. The effect of weed control × Cultivar interaction was significant only for on biological and grain yield. The highest plant height, branches per plant, chlorophyll index and nodule number and weight were obtained at weeding treatment and these traits decreased significantly in weedy conditions. The highest grain yield (136.00 g m-2) was obtained at Hashem cultivar in weeding conditions. The lowest value of this trait (33.00 g m-2) with about 75% reduction, was achieved to Mahali cultivar in no weeding condition. Maximum and minimum weed biomass and density was belonged Hashem and Mahali cultivars, respectively. Therefore, results showed that the highest competition index (2.16) belonged to Hashem cultivar, and the lowest value of this index (0.41) belonged to the Mahali cultivar. According to the results of this research, Hashem cultivar can be known as a resistant cultivar against weeds, but against the Mahali cultivar it has the lowest ability against weed invasion.

The results of this experiment showed that the yield of different cultivars of chickpea were decreased in the presence of weeds. However, yield reduction were not same in different cultivars. As a result, Hashem and local cultivars were identified as a strong and weak cultivar, respectively, in competition with weeds. By evaluating the different varieties of chickpea yield and competitiveness index, can be known which the varieties have good competitive ability in a condition of weed presence, and have the potential in combination with other weed control methods, produce more acceptable yields by lesser need for herbicides.